Matrix: Pothen/pwt

Description: pwt, with coordinates. From NASA, collected by Alex Pothen

Pothen/pwt graph
(undirected graph drawing)

Pothen/pwt dmperm of Pothen/pwt
Pothen/pwt graph

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  • Matrix group: Pothen
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  • download as a MATLAB mat-file, file size: 741 KB. Use UFget(880) or UFget('Pothen/pwt') in MATLAB.
  • download in Matrix Market format, file size: 585 KB.
  • download in Rutherford/Boeing format, file size: 532 KB.

    Matrix properties
    number of rows36,519
    number of columns36,519
    structural full rank?yes
    structural rank36,519
    # of blocks from dmperm57
    # strongly connected comp.57
    explicit zero entries0
    nonzero pattern symmetrysymmetric
    numeric value symmetrysymmetric
    Cholesky candidate?yes
    positive definite?no

    editorG. Kumfert, A. Pothen
    kindstructural problem
    2D/3D problem?yes

    Additional fieldssize and type
    coordfull 36519-by-3

    Ordering statistics:result
    nnz(chol(P*(A+A'+s*I)*P')) with AMD1,555,833
    Cholesky flop count1.6e+08
    nnz(L+U), no partial pivoting, with AMD3,075,147
    nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD2,667,503
    nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD5,000,519

    SVD-based statistics:
    null space dimension1,044
    full numerical rank?no
    singular value gap4.30451e+09

    singular values (MAT file):click here
    SVD method used:s = svd (full (A))

    Pothen/pwt svd

    For a description of the statistics displayed above, click here.

    Maintained by Tim Davis, last updated 12-Mar-2014.
    Matrix pictures by cspy, a MATLAB function in the CSparse package.
    Matrix graphs by Yifan Hu, AT&T Labs Visualization Group.